Process of manufacture of pulp and paper



Patented June 3, 1930 UNITED STATES PATENT orrlca No Drawing.

fibrous materials. The former were then LEVIS MILLER BOOTH, OF PLAINFIELD, NEW JERSEY PROCESS OF MANUFACTURE OF PULP AND PAPER Application filed October 22, 1927. Serial No. 228,104.

suitable quality of pulp. In my improved process I discontinue the washing after a fraction of the usual washing period or do not wash at all and add a coagulating substance, such as sulphate of aluminum, ferrous sulphate, or ferric sulphate and ferric separated from the latter by a washing procseparate process.

ess which results in the production of voluminous quantities of alkaline wash water carrying non-fibrous organic matter, as well as small amounts of fibrous material. processes heretofore practiced the alkaline wash water, together with its burdens of mineral and organic matter is either Wasted or treated by recovery or disposal processes. i I have found that it is possible to increase salt and chlorine.

the yield of paper or board and at the same 2 time to materially lessen the volume of wash water required by terminating the pulp washing process at a time when appreciable amounts of alkali still persist, which if left free in the pulp are detrimental in the sub-- or unwas 3o sequent paper or board making processes and to the product. I may eliminate washing entirely.

After digesting the pulpby an alkaline process I introduce into the pulp washer or washer beater or subsequently, an acid salt having a coagulating effect which permits the use of pulp containing more of alkali and non- By Claims.

fibrous matter than it. has been feasible to employ in the manufacture of paper or board 40 of the kind and quality cominonly acceptable in commerce. One example of the applica tion of m process which I have found to be practicab e is as follows:

For the manufacture of straw pa r or board straw is cooked in the presence 0 lime. The pulp is then washed for the urpose of removing the excess lime and nonbrous ma- 7 terial. "In one instance the washing process has heretofore been continued for a penod of approximately three hours to produce a chloride with the addition of chlorine. The treatment which I efi'ect causes the neutralization of the alkali to the required extent and further insures the retention of nonfibrous and fibrous material in the finished product which by processes heretofore used would be wasted or have to be recovered by :1

Besides conserving raw material I materially reduce the volume of Wash Water required or eliminate it entirely.

1. The process of treating partially washe or unwashed'pulp which has been digested by an alkaline process which consists of adding to such pulpa coagulating metallic 2. The process of treating partially washed or unwashed pulp which has been digested b y an alkaline process which consists of adding to such pulp ferrous sulphate and chlorine.

3. The recess of treating partially washed Bed pulp which has been digested by an alkaline process which consists of adding to. such pulp ferric sulphate, ferric chloride and chlorine.

4. The process of treating partially washed or unwashed pulp which has been digested 'by an alkaline process which consists of adding an acidifying substance and chlorine.

LEVIS MILLER BOOTH. 

